1. Field of the Invention
The present invention relates in general to a power supply characterized by small size, less noise and long life span.
2. Description of the Related Art
As shown in FIGS. 1 and 2, a conventional power supply has a housing 12, a printed circuit board (PCB) 16 received in the housing 12 and a plurality of electrical elements 18 attached onto the PCB 16. In operation, the temperature of the electrical elements 18 is high. Thus, a fan assembly 14 is provided to ventilate the inside of the power supply. Hot air in the housing 12 is drained out via holes 120 on the housing 12 so as to cool down the electrical elements 18.
The conventional power supply has many flaws: (1) The power supply is very thick because the fan assembly 14 is vertically arranged to ventilate the inside of the power supply. (2) The weight of the fan of the fan assembly acts laterally on the spinning shaft (not shown) of the fan due to the vertical arrangement of the fan assembly. In design, a lateral load on a spinning shaft should be avoided in order to prolong the life span of the shaft. (3) The conventional power supply is very noisy because the fan is disposed very close to the holes 120, which constitute the airflow outlet. This arrangement generates so called "Aerodynamic Noise".